As IP Multimedia Subsystem (IMS) Services grow in popularity, an increasing number of data and multimedia applications are envisioned for fixed and mobile IP-based communication devices. Currently, each IMS application establishes a new user interface at a terminal device. This approach is similar to the days when each software application essentially had its own look and feel, thereby resulting in the creation of various windowing systems to address this problem.
Today's IMS services are deployed according to a static model. That is, communication devices operating in a wired or wireless access network (WAN) such as shown in the prior art system of FIG. 1 have one or more IMS clients and applications loaded on them that are pre-provisioned with credentials (e.g., user name/password, HTTP digest, etc.). Each IMS client is supplied by a corresponding IMS service provider. Accordingly, each of these clients is pre-configured to point to a particular IMS service provider. The end user of a communication device utilizing these clients is thereby forced to subscribe with each corresponding IMS service provider on a fixed subscription.
As a result of this static model there is no easy way for a roaming user to subscribe to an IMS service on a temporary basis. A need therefore arises for a method and apparatus that delivers IMS services.